What are typical costs in Australia?

Typical roof mounted installs in the USA are in the $3-4/Watt range, inclusive of parts, labor, and permitting for professional installation. Tax credits and other incentives can reduce this.

Code compliant ground mount installs via DIY are in the $2.75-$4/Watt range, inclusive of all parts and permitting and assuming labor is free but that a licensed electrician is needed for final grid tie. Tax incentives can reduce this. Not needing permits or a licensed electrician also can reduce it. Alternatives such as using wood racking instead of metal is also cheaper but this may violate electric code.